A friend and I were sitting at a bar, iPhones in pockets, discussing our recent trips in Japan and how we’d like to go back. The very next day, we both received pop-up ads on Facebook about cheap return flights to Tokyo. It seemed like just a spooky coincidence, but then everyone seems to have a story about their smartphone listening to them. So is this just paranoia, or are our smartphones actually listening?

According to Dr. Peter Hannay—The senior security consultant for cybersecurity firm Asterisk, and former lecturer and researcher at Edith Cowan University—the short answer is yes, but perhaps in a way that’s not as diabolical as it sounds.

For your smartphone to actually pay attention and record your conversation, there needs to be a trigger, such as when you say “hey Siri” or “okay Google.” In the absence of these triggers, any data you provide is only processed within your own phone. This might not seem a cause for alarm, but any third party applications you have on your phone—like Facebook for example—still have access to this “non-triggered” data. And whether or not they use this data is really up to them.

“From time to time, snippets of audio do go back to [other apps like Facebook’s] servers but there’s no official understanding what the triggers for that are,” explains Peter. “Whether it’s timing or location-based or usage of certain functions, [apps] are certainly pulling those microphone permissions and using those periodically. All the internals of the applications send this data in encrypted form, so it’s very difficult to define the exact trigger.”